With the development of mobile communications technologies, a system can provide an increasingly high transmission rate and quality of service, and a user service also imposes an increasingly high requirement on the transmission rate. To ensure a rate for general users, and meanwhile, to provide a higher throughput for a part of users, in a situation where substantial increase of a configuration bandwidth is avoided, the 3GPP (third generation partnership project) introduces a carrier aggregation (Carrier Aggregation, CA) technology. Its solution is mainly that a user equipment (User Equipment, UE) may simultaneously use a plurality of component carriers (Component Carrier, CC) to perform uplink and downlink communication, thereby supporting data transmission at a high rate. When a user rate is lowered, some component carriers may be released and only one primary carrier is maintained, so that a released transmission resource may be used by another user, thereby achieving an objective of flexible and dynamic transmission.
According to a base station position where an aggregated carrier is located, carrier aggregation in an LTE (Long Term Evolution, long term evolution) system may be classified into manners, such as cell aggregation inside a base station and cell aggregation between base stations. The cell aggregation inside a base station means that component carriers simultaneously used by a UE are all controlled by the same base station, and the cell aggregation between base stations means that component carriers simultaneously used by a UE are controlled by different base stations. According to types of base stations where aggregated carriers are located, the cell aggregation between base stations may further be classified into manners, such as cell aggregation between macro base stations, and cell aggregation between a macro base station and a home base station (Home eNB, HeNB).
Because a shared channel is adopted for data transmission in the LTE system, after a UE establishes an RB (Radio Bearer, radio bearer) connection, if the UE has uplink data that needs to be sent, the UE requests a resource from an eNB (evolved NodeB, evolved base station) and transfers the uplink data by using an uplink resource allocated by the eNB. In a normal situation, the UE requests a resource from an eNB mainly through an SR (Scheduling Request, scheduling request) and a BSR (Buffer Status Report, buffer status report). Through the SR, the UE can only notify the eNB whether data to be transmitted exists, and the SR is sent by using a dedicated resource; and in a manner of the BSR, the UE can notify the eNB of the amount of the data to be transmitted, and the BSR is sent by using a shared resource, that is, a resource used for sending the BSR also needs to be obtained through a request made by the UE to the eNB.
In a mode of carrier aggregation, a UE may have a plurality of logical channels working simultaneously; and in a mode of carrier aggregation inside a base station, logical channels corresponding to cells are uniformly classified into groups. When the base station configures logical channel groups, correspondence between a logical channel and a cell is not considered, that is, logical channels in one logical channel group may correspond to one cell and may also correspond to different cells. After receiving a BSR, the eNB does not determine which cell corresponds to a logical channel having data to be transmitted. Therefore, the eNB only allocates an uplink resource of any one aggregated carrier to the UE, and after receiving the uplink data, the eNB may distribute the uplink data to processing entities of logical channels for processing.
However, in a mode of carrier aggregation between base stations, because logical channels of the UE may be distributed on a plurality of eNBs at a network side, if a manner of reporting a BSR in the mode of carrier aggregation inside a base station is continued to be used, the eNB cannot determine which cell corresponds to a logical channel having data to be sent, and if a cell where an allocated uplink resource is located and a cell corresponding to the logical channel belong to different eNBs, it may causes that data cannot be correctly processed.